A Comprehensive Geriatric Assessment (CGA) has become a fundamental aid in the evaluation and treatment planning of older cancer patients. Systematic reviews of trials of geriatric assessments have shown effectiveness when interventions are implemented. Although CGA is a fundamental tool in the care of the geriatric patient, the integration and application of this tool in oncologic practice are still in evolution. Cognition is one of the domains examined within a CGA. Studies have noted that up to 25% to 50% of older patients had cognitive abnormalities that warranted further evaluation. Cognitive dysfunctions can influence the ability to weigh the risks and benefits of cancer therapy, to comply with the suggested treatment plan, and to recognize the symptoms of toxicity that need medical attention. Recently, the Freund Clock Drawing Test (CDT) has been proposed as a quick and simple screening tool to assess cognitive dysfunction. A retrospective analysis on 105 cancer patients at the General Hospital Groeninge showed that a cut-off score of ≤ 4 for the CDT has a good AUC, sensitivity and specificity.